Need help choosing a modem

I have Business Class 75/15 service. Right now I have a Comcast supplied Cisco dpc3008 modem. I would like to buy my own modem to replace it and save the rental fee. This modem has worked great, but Comcast's device list says the retail version of it is not approved. I asked the support agent I chatted with if there was a modem on the list that he would recommend, and he said no. But I wound up with this modem several years ago after buying a Motorola Surfboard that was also on the list and which never worked right. So now I'm leery about buying another one. But it seems ridiculous to keep paying $14.95 a month for something that I can buy and which will pay for itself in less than a year.

Can anybody give me a recommendation for modems that are on the approved list and that would work well with my service tier? I'm in southern Delaware, zip 19968. I know location is important for this question.

Thanks!